Electrical switch having rotary movable contact with vane piston contact actuating means



March 1966 c. D. FLOESSEL ELECTRICAL SWITCH HAVING ROTARY MQVABLE CONTACT WITH VANE PISTON CONTACT ACTUATING MEANS Filed Oct. 29, 1963 I NVENTOR CaJrL DLe'lzer Floessel. PLM WMMM ATTORNEYS United States Patent v O 3,239,636 ELECTRICAL SWITCH HAVING ROTARY MOVA- BLE CONTACT WITH VANE PISTON CONTACT ACTUATIN G MEANS Carl Dieter Fioessel, Fislisbach, Switzerland, assignor to Aktiengesellschaft Brown, Boveri & Cie, Baden, Switzerland, a joint-stock company Filed Oct. 29, 1963, Ser. No. 319,745 Claims priority, application Switzerland, Dec. 20, 1962, 14,923/ 62 2 Claims. (Cl. 200-148) The present invention relates to an improved construction for gas blast breakers with multiple interruption, where at least one voltage isolating switching point is connected electrically in series with impulse-power switching points to insure in the disconnected position of the switch the insulation "over the open switch-ing gap, the voltage switching point being arranged in a switch chamber that is continually subjected to a pressurized gas.

It is known to design gas blast breakers so that several impulse-power switching points are connected in series, and that one or more voltage isolating switching points are connected likewise in series with the latter. The voltage isolating switching point, usually referred to as a disconnecting switch, can be designed either as a soseries disconnector with interruption in air, or as an interruption point which is arranged in a switch chamber filled with a pressurized gas. In the latter case, the movable contact piece is pinor tulip-shaped and performs a thrust movement in the switch to which end it is in driving connection with a pressure gas actuated piston. The actuation of the movable contact piece in the known series disconnectors, where the contact piece in the form of a blade shaped element turns about an axis of rotation, as well as in the known thrust blade switch, re-

quires relatively large driving and damping mechanisms respectively in the case of switches with higher rated voltages and higher rated currents, since large masses must be put in motion and braked respectively in order to meet the requirements of modern switches regarding short switching periods, particularly when the switch is to be used for short interruptions.

The problem underlying the invention is to provide a simple and inexpensive solution of a voltage switching point for high-speed gas blast breakers, where the above mentioned disadvantages of the known embodiments are avoided. According to the invention it is therefore suggested that the movable blade-shaped contact pieces of the voltage switching point be secured on a shaft supported in the switch chamber housing, and that the shaft be connected for rotation with a rotary piston drive whose vane piston movable in a cylinder can be admitted alternately with a pressurized gas from one and the other side in such a Way that pressurized gas from a storage vessel is used for disconnection and pressurized gas from the switch chamber for connection, the chamber which happens to be on the non-admitted side of the vane piston being in communication with the outside air.

This has the advantageus result that the driving gas is brought during connection along the shortest path to the rotary piston drive. Besides, the new arrangement requires no mechanical intermediate members, since the vane piston is secured on the same shaft that also carries the movable contact piece. This arrangement also has the advantage that the limiting positions of the movable contact piece are clearly fixed so that it cannot perform any unauthorized, automatic movement if the pressure should drop in the switch chamber or in the feed pipes to the rotary piston drive. The invention will be more fully described on the basis of a preferred embodiment and the attached drawings: In these:

3,239,636 Patented Mar. 8, 1966 'FIG. 1 shows an embodiment according to the invention where the switch chamber is partly represented in a section;

FIG. 2 shows a longitudinal section through the rotary piston drive attached laterally on the switch chamber according to FIG. 1; and

FIG. 3 shows a cross section through the rotary piston drive according to FIG. 2 along the line III-III.

With reference now to FIG. 1 the switch chamber housing 1 is terminated at both sides by the flange par-ts 2a, 2b, which are joined by the insulators 3a, 3b. 4 designates the blade-shaped contact piece of the voltage isolating switch which is connected rigidly with the drive shaft 5 and which is arranged symmetrically with the latter. The drive shaft 5 is rotatably mounted at its ends in known manner in the switch chamber housing 1. The two spaced fixed contact pieces 6a, 6b, which are preferably designed in known manner as contact brushes, and which are engaged respectively opposite ends of the switch knife 4 when the drive shaft 5 turns through in the direction indicated by the arrow, are rigidly connected with the conductors 7a, 7b, the latter being held by means of the insulating parts 8 and 9 and introduced insulated into the switch chamber housing 1. FIG. 2 shows a longitudinal section and FIG. 3 a cross section along the line III-I'II10f FIG. 2 of the rotary piston drive actuating the drive shaft 5. In the cylinder housing 1a, cast on the housing 1, for example, is guided the vane piston 10 rigidly connected with the drive shaft 5. This piston has at both sides disk-shaped valve elements 11a, 1117, which are rigidly connected with the vane piston in known manner, for example, by vulcanization. Into the cylinder housing 1a project, staggered by 90, the tubular nipples 12a, 12b which are designed as valve seats at at their ends facing the valve discs 11a, 11b on vane piston 10. The nipples 12a, 12b have at their outer end a collar and are pressed by means of the cup spring 13 against the sealing rings 14. The partition 15 serves to subdivide and reduce the size of the effective chambers 16a, 16b in the cylinder housing 1a. -17 is a cover (FIG. 3) which terminates the cylinder housing In laterally. F-IG. 2 shows furthermore in a section the cylindrical extension 1b which extends downward under switch-chamber housing 1. The extension 1b contains a reversing valve 18 which is conected over the valve rod 18a with the drive piston 13b. In the valve chamber '19 are arranged the sealing disks 20a and 20b, while the chamber 21 is connected with the open air through the apertures 22. The pressurized gas line 23 connects the chamber 24 under the drive piston 18b with that part of the cylinder housing 1a which houses the nipple 12a, while the pressurized gas line 25 leads from the chamber 19 containing the reversing valve to the nipple 12b. The interior of the switch chamber housing 1 is connected with the chamber 19 through the aperture 26 that can be closed by the reversing valve 13. Finally 27 designates a hollow supporting insulator which is rigidly connected with the extension 1b and which serves as a support for the entire switch chamber.

The method of operation of the above described arrangement is as follows: In the represented position (FIG. 1), the voltage switching point 4 is in the disconnected state. The interior of the switch chamber housing 1 is connected by way of a non-illustrated compressed gas line with a storage vessel, likewise not represented, of the gas blast breaker and is constantly under gas pressure. The interior of the supporting insulator 27 is connected through a switch valve of known design, not represented, on the lower part of the switch with the storage vessel of the latter and is thus likewise under pressure. The chamber 16a in the cylinder housing 1a is filled with pressurized gas through the line 23 and the nipple 120, which presses the vane piston 10 via its disk-shaped valve element 11b, which is designed preferably as an elastic sealing disk, firmly against the end of nipple 12b. The latter is connected through the line 25, the chambers 19 and 21, which communicate through the wide bore for the piston rod 18a, and the apertures 22 with the open air and is thus pressure-free. The aperture 26 between the switch chamber housing 1 and the chamber 19 is closed by the reversing valve 18, since the pressure in the chamber 24 retains the piston 18b and thus the reversing valve 18 in its upper limiting position. Since the nipple 12b in the cylinder housing 1a is yeldingly mounted by means of the sealing ring 14, inaaccuracies in the manufacture regarding a non-planar fit of the sealing disk 11b on the valve seat at the inner end of the nipple 12b are automatically compensated. For connection, to close the disconnect switch contacts 4, 6LI-6b, the interior of the supporting insulator 27 is ventilated by means of the above mentioned switch valve, not represented. In this way, on the one hand, chamber 24 under the drive piston 18b of the reversing valve 19 is ventilated, and on the other hand the chamber 16a is ventilated through the interior of the nipple 12a and the line 23. Under the action of the gas pressure in the switch chamber housing 1, which presses through the aperture 26 on the upper side of the reversing valve 18, the latter is brought into its bottom limiting position, so that the chamber 19 is closed from the open air. The movement of the reversing valve 18 can be enhanced, if necessary, by a return spring, not represented. As soon as the reversing valve 18 releases the aperture 26, pressure gas flows from the switch-chamber housing 1 through this aperture 26 into the chamber 19 and thence through the line 25 into the nipple 12b so that vane piston 10 is now turned counterclockwise through 90 and chamber 16b is filled with pressure gas. Chamber 16a is ventilated, as already mentioned and reduced in size during the rotation of the vane piston 10 until the latter strikes with its sealing disk 11a against the nipple 12a. The connecting position of the voltage switching point 4, 611-617 has thus been reached, since the drive shaft connected with the vane piston has brought the movable contact piece 4 (FIG. 1) into the horizontal position, in which the contact piece 4 engages at both ends the fixed contact pieces 6a, 6b. Subsequent disconnection is efiected again by introducing pressurized gas into the interior of the supporting insulator 27, filling the chamber 24, the line 23 and the chamber 16a, and causing the reversing valve 18 to move into its upper limiting position. The chamber 19, and thus the line 25, as well as the chamber 16b are connected again with the open air so that the vane piston 10 performs a clockwise rotation through 90 which brings it finally into the represented limiting position. To this position corresponds again the disconnection of the voltage switching point, represented in FIG. 1.

I claim:

1. In a gas blast circuit breaker comprising at least one set of power interrupting contacts of the impulse type connected in series with the separable contact members of a voltage isolating switch to insure an adequate voltage isolation in the switched-out position of the circuit breaker, the improvement wherein said voltage isolating switch is comprised of at least one stationary contact member located in a switch chamber filled with a pressurized gas and a movable blade shaped contact member mounted on a rotatable shaft to engage and be disengaged from said stationary contact member, a rotary piston type drive for said shaft including a vane piston secured to said shaft and mounting for rotation in a cylinder between two limiting positions corresponding respectively to the engaged and disengaged positions of the contact members of said voltage isolating switch, said vane piston including a disc-shaped valve plate at each side thereof, a pair of nipples extending into said cylinder at opposite sides of said vane piston, the mouths of said nipples being cooperative respectively with said valve plates in alternation such that the mouth of one nipple is closed by the associated valve plate when pressurized gas is admitted through the other nipple, and control valve means for selectively admitting pressurized gas into said cylinder through one of said nipples at one side or the other of said vane piston and simultaneously venting to atmosphere through the other of said nipples the interior of said cylinder at the non-admitted side of said vane piston, the pressurized gas from said switch chamber being admitted into said cylinder at one side of said vane piston for rotating said vane piston and movable blade shaped contact member in such direction as to engage said stationary contact member, and pressurized gas from a storage vessel being admitted into said cylinder at the opposite side of said vane piston for rotating said piston and said movable blade shaped contact member in such direction as to disengage itself from said stationary contact member.

2. A gas blast circuit breaker as defined in claim 1 wherein said nipples are mounted in a yielding manner to compensate for any misalignment of the corresponding valve plate.

References Cited by the Examiner UNITED STATES PATENTS 2,350,066 5/1944 Parker 92121 X FOREIGN PATENTS 1,099,616 2/1961 Germany.

794,204 4/ 1958 Great Britain.

KATHLEEN H. CLAFFY, Primary Examiner. 

1. IN A GAS BLAST CIRCUIT BREAKER COMPRISING AT LEAST ONE SET OF POWER INTERRUPTING CONTACTS OF THE IMPULSE TYPE CONNECTED IN SERIES WITH THE SEPARABLE CONTACT MEMBERS OF A VOLTAGE ISOLATING SWITCH TO INSURE AN ADEQUATE VOLTAGE INSOLATION IN THE SWITCHED-OUT POSITION OF THE CIRCUIT BREAKER, THE IMPROVEMENT WHEREIN SAID VOLTAGE ISOLATING SWITCH IS COMPRISED OF AT LEAST ONE STATIONARY CONTACT MEMBER LOCATED IN A SWITCH CHAMBER FILLED WITH A PRESSURIZED GAS AND A MOVABLE BLADE SHAPED CONTACT MEMBER MOUNTED ON A ROTATABLE SHAFT TO ENGAGE AND BE DISENGAGED FROM SAID STATIONARY CONTACT MEMBER, A ROTARY PISTON TYPE DRIVE FOR SAID SHAFT INCLUDING A VANE PISTON SECURED TO SAID SHAFT AND MOUNTING FOR ROTATION IN A CYLINDER BETWEEN TWO LIMITING POSITIONS CORRESPONDING RESPECTIVELY TO THE ENGAGED AND DISENGAGED POSITIONS OF THE CONTACT MEMBERS OF SAID VOLTAGE ISOLATING SWITCH, SAID VANE PISTON INCLUDING A DISC-SHAPED VALVE PLATE AT EACH SIDE THEREOF, A PAIR OF NIPPLES EXTENDING INTO SAID CYLINDER AT OPPOSITE SIDES OF SAID VANE PISTON, THE MOUTHS OF SAID NIPPLES BEING COOPERATIVE RESPECTIVELY WITH SAID VALVE PLATES IN ALTERNATION SUCH THAT THE MOUTH OF ONE NIPPLE IS CLOSED BY THE ASSOCIATED VALVE PLATE WHEN PRESSURIZED GAS IS ADMITTED THROUGH THE OTHER NIPPLE, AND CONTROL VALVE MEANS FOR SELECTIVELY ADMITTING PRESSURIZED GAS INTO SAID CYLINDER THROUGH ONE OF SAID NIPPLES AT ONE SIDE OR THE OTHER OF SID VANE PISTON AND SIMULTANEOUSLY VENTING TO ATMOSPHERE THROUGH THE OTHER OF SAID NIPPLES THE INTERIOR OF SAID CYLINDER AT THE NON-ADMITTED SIDE OF SAID VANE PISTON, THE PRESSURIZED GAS FROM SAID SWITCH CHAMBER BEING ADMITTED INTO SAID CYLINDER AT ONE SIDE OF SAID VANE PISTON FOR ROTATING SAID VANE PISTON AND MOVABLE BLADE SHAPED CONTACT MEMBER IN SUCH DIRECTION AS TO ENGAGE SAID STATIONARY CONTACT MEMBER, AND PRESSURIZED GAS FROM A STORAGE VESSEL BEING ADMITTED INTO SAID CYLINDER AT THE OPPOSITE SIDE OF SAID VANE PISTON FOR ROTATING SAID PISTON AND SAID MOVABLE BLADE SHAPED CONTACT MEMBER IN SUCH DIRECTION AS TO DISENGAGE ITSELF FROM SAID STATIONARY CONTACT MEMBER. 